Magnesium alloys have begun to be rapidly in widespread use as casing of cell phones or laptop computers, and as automobile parts, along with the recycling performance thereof.
To be used for these uses, however, the magnesium alloys are required to have high strength and high toughness. For the manufacture of high-strength and high-toughness magnesium alloy, various studies have been conducted from the viewpoint of materials and the like.
According to a disclosure of the inventors of the present invention, an ingot of magnesium alloy having a composition of 97 atom % Mg-1 atom % Zn-2 atom % Y forms a long-period stacking ordered structure therein, and high strength and high toughness are obtained at room temperature by applying extrusion working to the ingot, (for example, refer to Patent Document 1).    [Patent Document 1] WO 2005/052203